JP4845847B2 - Disc spring - Google Patents

Description

  The present invention relates to a disc spring used for absorbing shocks generated when a clutch of a multi-plate clutch mechanism of a transport machine is engaged, and more particularly to an improvement technique for a disc spring having teeth for preventing relative rotation with respect to a clutch drum. .

  A wet multi-plate clutch mechanism is used as a clutch mechanism in a transmission of a transport machine. The wet multi-plate clutch mechanism uses a disc spring that absorbs shock generated when the clutch is engaged. FIG. 3 is an enlarged side sectional view showing a configuration of a multi-plate clutch mechanism 100 to which a conventional disc spring 200 is applied. The multi-plate clutch mechanism 100 includes a clutch drum 101 having a substantially bottomed cylindrical shape, and a plurality of spline grooves 101A extending in the axial direction are formed in the circumferential direction on the inner peripheral surface thereof. Inside the clutch drum 101, a cylindrical clutch hub 102 whose rotational axis line coincides with it is provided, and a plurality of spline grooves 102A extending in the axial direction are formed in the circumferential direction on the outer peripheral surface thereof.

  Between the clutch drum 101 and the clutch hub 102, a driven plate 103 fitted in the spline groove 101A of the clutch drum 101 and a drive plate 104 fitted in the spline groove 102A of the clutch hub 102 move in the axial direction. They are arranged alternately at a predetermined interval. A piston 105 is provided on the bottom surface side of the clutch drum 101 so as to be movable in the axial direction. A hydraulic chamber 106 is formed between the piston 105 and the clutch drum 101.

  Between the driven plate 103 on the bottom surface side of the clutch drum 101 and the piston 105, a disc spring 200 having a circular disc shape with a hole formed in the center is provided. The disc spring 200 is arranged such that the outer peripheral edge surface is supported by the driven plate 103 and the inner peripheral edge back surface is supported by the piston 105.

  In the multi-plate clutch mechanism 100 as described above, when hydraulic oil is supplied to the hydraulic chamber 106, the piston 105 driven by the hydraulic pressure presses the driven plate 103 on the bottom surface side of the clutch drum 101 via the disc spring 200. . Then, the driven plate 103 on the bottom side moves to the opening side of the clutch drum 101, the friction surfaces of the driven plate 103 and the drive plate 104 facing each other engage, and the clutch is engaged. At this time, the disc spring 200 absorbs a shock generated at the time of clutch engagement by elastically deforming so as to be substantially flat from the disc shape.

  Incidentally, since the disc spring 200 has a circular shape, the disc spring 200 easily rotates relative to the clutch drum 101 when the clutch mechanism 100 rotates. For this reason, there is a problem that the disc spring 200 frequently collides with the inner wall of the clutch drum 101, and as a result, the inner wall of the clutch drum 101 is damaged.

  Therefore, in order to solve the above problem, as shown in FIG. 4, a disc spring in which a plurality of teeth 311 are formed on the outer peripheral portion of a main body 310 having a circular plate shape with a hole 310A formed at the center. 300 has been proposed (for example, Patent Document 1 and Patent Document 2). In the disc spring 300, the main body 310 is installed inside the clutch drum 101 so that its teeth 311 are fitted with the spline groove 101A on the inner peripheral surface of the clutch drum 101. Rotation can be prevented.

JP 2001-295860 A JP-A-9-329155

  However, the disc spring 300 has a problem that the durability of the disc spring 300 is greatly reduced because stress concentration occurs at the root portion of the tooth 311 during elastic deformation at the time of clutch engagement.

  Therefore, in order to reduce the generated stress at the root portion of the tooth 311, it is conceivable to increase the curvature radius R of the arc portion 311 </ b> A at the root portion of the tooth 311. However, in this case, since the arc portion 311A of the root portion of the tooth 311 projects outward in the radial direction so as to expand in the circumferential direction, the clutch drum 101 has a sharp shape when the spline groove 101A of the clutch drum 101 is sharp. A large interference occurs between the tooth 311 and the spline groove 101A during the rotation of. For this reason, wear of the spline groove 101A by the teeth 311 increases. Further, since the length L of the straight portion 311B of the side surface portion of the tooth 311 is reduced, the fitting area of the tooth 311 with the spline groove 101A is reduced. For this reason, the contact surface pressure between the tooth 311 and the spline groove 101A increases, and wear of the spline groove 101A by the tooth 311 increases. In particular, since the disc spring 300 is required to have high durability in order to cope with the increase in the guaranteed traveling distance of automobiles in recent years, the above problems are serious.

  Accordingly, an object of the present invention is to provide a disc spring that can reduce the generated stress at the root portion of the tooth when the clutch is engaged, and can reduce the wear of the spline groove due to the tooth. Yes.

The disc spring according to the present invention is a disc spring disposed between a second member and a third member that are provided so as to be movable in the axial direction inside the cylindrical first member, and has a circular disc shape. A tooth that fits into a groove formed on the inner peripheral surface of the first member is formed on the outer peripheral portion of the main body so as to protrude radially outward, and is a boundary portion between the outer peripheral portion of the main body and the side surface portion of the tooth. the root portion of the tooth, the stress relaxation section with a flat portion or a curved portion which forms a flat or curved surface extending from the edge portion of the arcuate portion toward at least one direction of the circumferential direction and the radial direction of the root portion of the tooth It is characterized by having formed.

  In the disc spring of the present invention, the root portion of the tooth is provided with a stress relaxation portion in which the edge portion of the arc portion of the root portion of the tooth is planar or curved in at least one of the circumferential direction and the radial direction. When the disc spring is disposed between the driven plate and the piston of the clutch mechanism of the transport machine, the stress concentration generated at the root of the tooth when the clutch is engaged can be dispersed and alleviated by the stress relaxation portion. Therefore, the stress which generate | occur | produces in the root part of a tooth at the time of clutch fastening can be reduced. Further, even when the shape of the spline groove of the clutch drum is sharp, since the root portion of the tooth does not protrude radially outward, interference between the tooth and the spline groove during rotation of the clutch drum can be prevented. Thereby, abrasion of the spline groove due to teeth can be reduced. Further, since the straight portion of the side surface portion of the tooth is long, the fitting area with the tooth spline groove is increased, and the contact surface pressure between the tooth and the spline groove can be reduced. Thereby, the wear of the spline groove due to the teeth during rotation of the clutch drum can be greatly reduced. Therefore, since it can have high durability, it can respond to the increase in the guaranteed mileage of the automobile.

(1) Configuration of Embodiment (A) Disc Spring Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1A and 1B are views showing a configuration of a disc spring 1 according to the first embodiment of the present invention, in which FIG. 1A is a plan view, FIG. 1B is a side sectional view taken along line BB in FIG. ) Is a partially enlarged view of (A). The disc spring 1 includes a main body 10 having a circular dish shape, and a circular hole 10 </ b> A is formed at the center of the main body 10. A plurality of (for example, six) teeth 11 that are substantially rectangular and project outward in the radial direction are formed on the outer peripheral portion of the main body 10 at equal intervals in the circumferential direction.

  For example, when the teeth 11 are applied to the clutch mechanism 100 described below, the teeth 11 have a function of preventing the disc spring 1 from rotating relative to the clutch drum 101. Note that the tooth to which the present invention is applied is not limited to the tooth 11 shown in FIG. For example, the present invention can be applied to teeth having a shape extending along the outer peripheral surface of the main body 10 without being bent with respect to the outer peripheral surface of the main body 10. Moreover, although the number of the teeth 11 was set to 6, it is not limited to this, The number can be set arbitrarily.

  A stress relieving portion 12 having a flat portion 12B is formed at the root portion of the tooth 11. The flat part 12B is formed by processing the edge part in the circular arc part 12A of the root part of the tooth 11 into a planar shape by, for example, coining. When applied to the clutch mechanism 100 described below, for example, the stress relieving portion 12 has a function of relieving stress concentration generated at the root portion of the tooth 11 when the clutch is engaged.

  The coining process is performed at a desired position of the plate-shaped spring material before the press processing for forming the hole 10A and the teeth 11 at the center of the main body 10 into the plate-shaped spring material. Note that the edge portion of the arc portion 12A at the base of the tooth 11 may be a curved surface portion 12B having a curved surface shape by coining instead of the flat portion 12B having a planar shape by coining processing.

(B) Clutch mechanism The above-described disc spring 1 can be applied to a clutch mechanism 100 as shown in FIG. 2A and 2B show a configuration of the clutch mechanism 100, where FIG. 2A is an enlarged side sectional view and FIG. 2B is an exploded view. In FIG. 2B, illustration of the clutch hub 102 is omitted.

  Clutch mechanism 100 is a wet multi-plate clutch used in, for example, an AT car of an automobile. The clutch mechanism 100 includes a clutch drum 101 (first member) having a substantially bottomed cylindrical shape, and a plurality of spline grooves 101A extending in the axial direction are formed at equal intervals in the circumferential direction on the inner peripheral surface thereof. ing. A cylindrical clutch hub 102 whose rotational axis line coincides with the clutch drum 101 is provided inside the clutch drum 101, and a plurality of spline grooves 102 </ b> A extending in the axial direction are arranged at equal intervals in the circumferential direction on the outer peripheral surface thereof. Is formed.

  Between the clutch drum 101 and the clutch hub 102, a disk-shaped driven plate 103 (second member) having a circular hole formed at the center thereof and a drive plate 104 are alternately arranged at a predetermined interval. Is arranged. In the driven plate 103, a plurality of teeth are formed on the outer peripheral edge at equal intervals in the circumferential direction, and these teeth are fitted in the spline groove 101A. As a result, the driven plate 103 cannot rotate relative to the clutch drum 101 but can move in the axial direction. In the drive plate 104, a plurality of teeth are formed on the inner peripheral edge at equal intervals in the circumferential direction, and these teeth are fitted in the spline groove 102A. Thus, the drive plate 104 cannot move relative to the clutch hub 102 but can move in the axial direction.

  A piston 105 (third member) is disposed on the bottom surface side of the clutch drum 101 so as to be movable in the axial direction. A hydraulic chamber 106 to which hydraulic oil is supplied is formed between the bottom surface of the clutch drum 101 and the piston 105. The piston 105 is driven in the axial direction by hydraulic oil supplied to the hydraulic chamber 106. One end of a return spring 107 that is expanded and contracted by pressure applied thereto is fixed to the opening side surface of the piston 105. The other end of the return spring 107 is fixed to a spring retainer 108 provided on the clutch drum 101. The return spring 107 biases the piston 105 toward the bottom surface side of the clutch drum 101.

  The disc spring 1 is disposed between the driven plate 103 on the bottom side of the clutch drum 101 and the piston 105. In this case, the disc spring 1 is configured such that the teeth 11 are spline-fitted into the spline grooves 101 </ b> A and the outer peripheral edge surface of the main body 10 is supported by the driven plate 103 and the inner peripheral edge of the main body 10. Is arranged so that the back surface thereof is supported by the piston 105. Thus, the disc spring 1 cannot move relative to the clutch drum 101 but can move in the axial direction.

  On the opening side of the clutch drum 101, a retaining plate 109 for restricting the driven plate 103 and the drive plate 104 from moving in the axial direction by a predetermined amount or more is disposed. In the retaining plate 109, a plurality of teeth are formed on the outer peripheral edge at equal intervals in the circumferential direction, and these teeth are fitted in the spline groove 101A. As a result, the retaining plate 109 cannot move relative to the clutch drum 101 but can move in the axial direction. On the opening side surface of the retaining plate 109, a snap ring 110 is disposed to prevent the retaining plate 109 from being detached to the outside. The snap ring 110 is locked in a ring groove formed at the opening side end of the clutch drum 101.

(2) Operation of Embodiment Next, the operation of the clutch mechanism 100 to which the disc spring 1 is applied will be described mainly with reference to FIG.

  When hydraulic oil is supplied to the hydraulic chamber 106, the piston 105 driven by the hydraulic pressure moves to the opening side in the axial direction against the urging force of the return spring 107, and the bottom side of the clutch drum 101 via the disc spring 1. The driven plate 103 is pressed. Then, the driven plate 103, the drive plate 104, and the retaining plate 109 that are alternately arranged move to the opening side in the axial direction. When the retaining plate 109 is pressed against the snap ring 110 by such movement, the friction surfaces of the driven plate 103 and the drive plate 104 facing each other are engaged and the clutch is engaged. Thereby, torque transmission between the clutch drum 101 and the clutch hub 102 becomes possible.

  At this time, the disc spring 1 absorbs a shock generated when the clutch is engaged by elastically deforming so as to be substantially flat from the disc shape. In this case, the stress generated in the root portion of the tooth 11 during the elastic deformation of the disc spring 1 is reduced by the stress relaxation portion 12. Further, since the stress relieving portion 12 does not protrude outward in the radial direction, interference between the teeth 11 and the spline groove 101A during the rotation of the clutch drum 101 is prevented.

  Next, when the supply of hydraulic oil to the hydraulic chamber 106 is stopped, the piston 105 is pushed back to the bottom surface side of the clutch drum 101 by the urging force of the return spring 107. Then, the engagement of the friction surfaces of the driven plate 103 and the drive plate 104 is released, the clutch engagement is released, and the shape of the disc spring 1 returns to the original state.

  In the disc spring 1 of the present embodiment, the stress relaxation is such that the edge portion of the arc portion 12 of the root portion of the tooth 11 is planar or curved in at least one of the circumferential direction and the radial direction at the root portion of the tooth 11. Since the disc spring 1 is arranged between the driven plate 103 and the piston 105 of the clutch mechanism 100 of the transport machine, the stress relief unit 12 generates the root portion of the tooth 11 when the clutch is engaged. It is possible to disperse and relieve stress concentration. Therefore, the stress which generate | occur | produces in the root part of the tooth | gear 11 at the time of clutch fastening can be reduced. Further, even when the shape of the spline groove 101A of the clutch drum 101 is sharp, the root portion of the tooth 11 does not protrude outward in the radial direction, so that interference between the tooth 11 and the spline groove 101A during rotation of the clutch drum 101 is prevented. Can be prevented. Thereby, wear of the spline groove 101A by the teeth 11 can be reduced. Moreover, since the linear part of the side part of the tooth | gear 11 is long, the fitting area with the spline groove | channel 101A of the tooth | gear 11 becomes large, and the contact surface pressure of the tooth | gear 11 and the spline groove | channel 101A can be made small. Thereby, the wear of the spline groove 101A due to the teeth 11 during the rotation of the clutch drum 101 can be greatly reduced. Therefore, since it can have high durability, it can respond to the increase in the guaranteed mileage of the automobile.

(6) Modifications While the present invention has been described with reference to the above embodiment, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the embodiment described above, the disc spring of the present invention is applied to a wet multi-plate clutch used in an AT car of an automobile, but the present invention is not limited to this. For example, the disc spring of the present invention can be applied to a multi-plate clutch mechanism of a transport machine such as a construction machine or a motorcycle.

It is a figure showing the structure of the disc spring which concerns on 1st Embodiment of this invention, (A) is a top view, (B) is a sectional side view of the BB line of (A), (C) is (B). FIG. It is a figure showing the structure of the clutch mechanism to which the disc spring of FIG. 1 is applied, (A) is an expanded sectional side view, (B) is an exploded view. It is side sectional drawing showing the structure of the multi-plate clutch mechanism to which the conventional disc spring is applied. It is a figure showing the structure of the other conventional disc spring, (A) is a top view, (B) is a sectional side view of the BB line of (A), (C) is the elements on larger scale of (A). is there.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Belleville spring, 10 ... Main body, 11 ... Teeth, 12 ... Stress relaxation part, 12A ... Arc part, 12B ... Flat part, curved surface part, 101 ... Clutch drum (1st member), 103 ... Driven plate (2nd member) ), 101A: Spline groove (groove), 105: Piston (third member)

Claims (1)

In the disc spring disposed between the second member and the third member provided to be movable in the axial direction inside the cylindrical first member,
On the outer periphery of the circular dish-shaped main body, teeth that fit into grooves formed on the inner peripheral surface of the first member are formed so as to protrude radially outward,
The root portion of the tooth, which is a boundary portion between the outer peripheral portion of the main body and the side surface portion of the tooth, extends from the edge portion of the arc portion of the root portion of the tooth toward at least one of the circumferential direction and the radial direction. disc spring, characterized in that the formation of the stress absorbing portions having a flat portion or a curved portion forming a flat or curved to standing.

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